My wife and I have often enjoyed holidays in Australia. A year or two ago, we returned to Noosa, and visited a café where we remembered having had good coffee a year earlier.

As he handed us our coffees, I asked the barista whether he was the Kiwi we recalled having met there briefly on our previous visit. To my surprise, he stiffened, glared at me and said through clenched teeth, “I’m a proud Australian”, and stalked off. We drank our coffees and did not return.

It prompted me to wonder, however, what had led him to react as though an innocent inquiry had grievously insulted him?

The incident was, at one level, of little consequence and we had many perfectly pleasant interactions with many other Australians during our holiday. But it has stayed with me, and I cannot help but recall it when, as has happened recently with increasing frequency, there is some fresh report of Kiwis now living in “the lucky country” being discriminated against and denied the usual rights of citizenship.

My mother, as it happens, was born in Australia and, like most Kiwis, I was brought up with the belief that we and the Aussies were “brothers in arms” – an article of faith reinforced each year as we jointly celebrate Anzac Day. We are assured constantly by our respective leaders that our close relationship is in our DNA – so where did this apparent hostility to New Zealanders come from?

The question is important, since if one side singles out the other for unfair treatment, what can be left of the relationship we have valued so dearly? If it is to be preserved, we need to understand what is going wrong.

I think I can have a pretty good shot at identifying what it is that lies behind Australian attitudes – and the answer is not encouraging. Most societies find it easy to be open-minded and welcoming when things are going well. But when times are harder, the stresses and strains mean that attitudes change – and the Aussies are no exception.

Even when – by virtue of the boom in mineral prices – Australians enjoyed growing prosperity and full employment, and Kiwis crossed the Tasman in droves in search of well-paid jobs, there was no doubt some resentment at those seen as at best opportunists and at worst as bludgers. The Aussies learnt to be somewhat contemptuous of their trans-Tasman neighbours.

That sentiment has no doubt changed direction a lttle as the Australian economy has slowed over recent years. But, when the going gets tougher, the search for someone to blame gathers pace – and anyone who is seen to be not “one of us” is likely to cop it.

And that is especially so when a little dose of Aussie racism is added to the mix. In many Australian minds, “Kiwi” means Maori or Polynesian – and that, sadly, is likely to be a further cause of hostility.

Paradoxically, the view that Kiwis cross the Tasman to make an unjustified grab for a share of hard-earned Australian prosperity has survived even when the cross-Tasman migration has begun to shift in the other direction.

It is as though the Aussies, having resented what they saw as Kiwi opportunism when the going was good, now resent the fact that Australia’s good fortune has recently diminished – and again, look for someone to blame or at least take it out on.

Whatever the reasons, our leaders must surely have the gumption to impress on their Australian counterparts that discrimination against Kiwis who have made their lives in Australia is doing significant damage to our relationship.

I like to think that, give or take the odd underarm bowling episode, we and the Aussies remain best mates, and that we share the view that everyone deserves a “fair go”. On this side of the Tasman, we should strive to make sure that that remains the case. If the relationship has become a little fractious, we must resist the temptation to retaliate. They might send us myrtle rust, but we should show them what the Anzac spirit means – perhaps by allowing them to win the odd Super Rugby match. Mind you, it would have to be pretty odd!

I agree. But we can’t legislate for individual attitudes. We can, however, avoid enshrining a discrimination against our trans-Tasman cousins in our legislation which is what the Australian government is clearly doing.

And it’s driven largely by the Australian government being hell-bent on making every policy it can anti-New Zealand. The student loan example is the latest. I think people forget how influential government policy can be for the way its citizens think. It’s not all one-way traffic.